1. Field of the Invention
The present invention relates to an inclinometer system. More particularly, the present invention relates to an inclinometer system capable of detecting the inclination of the ground using a fiber bragg grating sensor to precisely measure the deformation of the ground.
2. Description of the Related Art
It is necessary to inspect the displacement of civil engineering structures, such as roads, tunnels, bridges, and dams, an inclined plane, an incision cliff, a subway construction site, and underground foundation work for skyscrapers, or the ground subsidence displacement of a reclamation land and a soft ground by detecting the displacement of the structures or the sidewalls according to the design standard for the structures or construction techniques used in the construction sites.
Generally, there are many measurement devices employing inclinometer sensors used for civil engineering. The measurement devices have various external appearances suitable for various civil engineering construction sites. For instance, the measurement device is buried in the ground or attached to the civil engineering structure by inputting the measurement device including inclinometer sensors, which have a predetermined length and assembled with each other using bolts, into an inclinometer casing. In a civil engineering field, the inclination displacement of the inclinometer sensor is converted into length (mm) to find the tilt degree of the civil engineering structure or the degree of ground subsidence, and such data are utilized to determine the stability of a civil engineering site.
Hereinafter, description will be made regarding the installation of a conventional representative inclinometer system for a civil engineering structure used in a civil engineering site.
FIG. 1 is a sectional view showing the conventional inclinometer system buried in the ground.
As shown in FIG. 1, in order to measure the inclination of a ground 10, after burring a single inclinometer casing 11 in the ground 10, a plurality of inclinometer sensors 12A and 12B are pushed into the inclinometer casing 11 using a plurality of sensor rollers 13A and 13B attached thereto while the inclinometer sensors 12A and 12B are being connected to each other using a plurality of bolts 14A and 14B. The inclinometer casing 11 is formed by connecting unit pipes having a length of about 3 m with each other, and substantially forms a single pipe.
Accordingly, after the conventional inclinometer system detects lateral underground displacement 16 using inclinometer sensors 12A and 12B, the inclinometer system collects measured data through a plurality of cables 15A and 15B exposed to the outside of the sensors 12A and 12B to determine the underground displacement.
However, the conventional inclinometer system or a ground subsistence measuring system has a very complicated structure, and is difficult to be installed. In detail, only the single inclinometer casing 11 is used to measure the inclination and the subsidence of the ground 10. Accordingly, the inclinometer system indirectly measures the inclination degree of the inclinometer casing by allowing the inclinometer sensors 12A and 12B to detect the displacement of the inclinometer casing transferred through the sensor rollers 13A and 13B in contact with internal grooves of the inclinometer casing. Therefore, the measured inclination degree of the inclinometer casing makes a great difference from an actual displacement of the inclinometer casing.